1. Field of the Invention
The present invention relates to a pattern formation technology in a process of manufacturing a semiconductor device, and in particular, to a pattern correcting method, a mask making method, a method of manufacturing a semiconductor device, a pattern correction system, and a computer-readable recording medium having a patter correction program recorded therein, which are capable of improving precision in forming fine patterns.
2. Description of the Related Art
In recent years, as the miniaturization of patterns formed on a semiconductor wafer has progressed, the problem that a final finished dimension of a pattern actually formed is not the same as a dimension of a desired design pattern has been brought about. In order to solve such a problem, some technologies in which, for example, a mask pattern different from a design pattern is made have been proposed. Those technologies are disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication Nos. 9-319067, 11-102062, and 2003-17390, and the like. Hereinafter, such technologies are called mask data processings. The mask data processings include, for example, mask data processing called process proximity correction (PPC) processing. The PPC processing is carried out in order to correct an error (processing conversion difference) called a process proximity effect (PPE) which occurs in each of various processes such as a lithography process and an etching process.
It has been known that a processing conversion difference occurring in each process described above is varied by another pattern disposed in the vicinity of a correction object pattern, which is about several μm from the correction object pattern. Further, it has been known that, a processing conversion difference occurring in, in particular, an etching process or a mask process is varied by, not only a pattern disposed in the vicinity of the correction object pattern, but also another pattern disposed at a position which is relatively distant from the correction object pattern, namely, which is about several ten μm to several mm from the correction object pattern. Such technology for avoiding a processing conversion difference by a long-distant pattern is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-17390. This technology is that a dummy pattern is inserted into a pattern forming region, and the variations of the layouts of other patterns at a long distance from the correction object patterns are reduced, and whereby an effect on a processing conversion difference from the long-distant pattern with respect to the correction object pattern is reduced.
As described above, Jpn. Pat. Appln. KOKAI Publication No. 2003-17390 discloses the technology in which an effect on a processing conversion difference from a long-distant pattern is reduced by inserting a dummy pattern into a pattern forming region. However, there are cases in which a dummy pattern cannot be disposed depending on a device structure. In this case, in accordance with the technology in Jpn. Pat. Appln. KOKAI Publication No. 2003-17390 described above, an effect on a processing conversion difference from a long distance cannot be reduced. Accordingly, another technique for correcting an effect from a long-distant pattern onto the correction object pattern is required.
However, in a case of correcting a pattern in consideration of an effect from a long-distant pattern onto the correction object pattern, the following two problems are brought about. One is the problem that a time until a correction value (correction amount) with respect to the correction object pattern is determined is easily increased. The reason for this is as follows. In the case of correcting a pattern in consideration of an effect from a long-distant pattern onto the correction object pattern, it is necessary to estimate effects from long-distant patterns onto respective correction object patterns for each correction object pattern, and to determine correction values in accordance with each effect. Therefore, a time until a correction value (correction amount) with respect to the correction object pattern is determined is increased as a distance from the correction object pattern to the long-distant pattern increases. The other one is the problem that a processing time required for correction and a data amount which must be considered are easily increased considerably. The reason for this is as follows. For example, when design data of a pattern to be formed has a hierarchical structure, the farther the distance from a correction object pattern to another pattern for being referred at the time of correction is, the more the data are expanded. Consequently, a processing time required for correction and a data amount which must be considered are increased considerably.
The problems bring about increases in a PPC processing time, a PPC verification time, a mask drawing time, and the like, and greatly affect a turn around time (TAT) in making of a device. As a result, there is a great concern that a reduction in the production efficiency and a steep rise in the production cost of the semiconductor device are brought about.